Disk brake



July 24, 1951 J. c. MCCUNE 2,561,445

DISK BRAKE Filed March 12, 1947 5 Sheets-Sheet 1 INVENTOR JOSEPH C. McCU NE m @42 Li.) ATTORNEY July 24, 1951 Y J. c. MCCUNE 2,561,445

DISK BRAKE Filed March 12. 1947 V 5 Sheets-Sheet 2 INVENTOR J SEPH c. MCQUNE twwm Jul ATTORNEY July 24, 1951 J, c, M cuNE 2,561,445

DISK BRAKE Filed March 12, 1947 5 Sheets-Sheet 4 INVENTOR JOSEPH c. McCUNE gw m ,ZL: ATTORNEY July 24, 1951 J. c. MOCUNE 2,551,445

msx BRAKE Filed March 12, 1947 I 5 Sheets-Sheet 5 IN VEN TOR Joseph C Mcune BY QIJ.

Ala ATTORNEY Patented July 24, 1951 DISK BRAKE Joseph C. McCune, Edgewood, Pa minor to ,The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application March 12, 1947, Serial No. 734,001

22 Claims. 1

This invention relates to vehicle brakes, and more particularly to disk type brakes for use on railway vehicles.

In accordance with the tempo of industrial progress, modern railway trains are increasing in speed. The vehicles of these trains must be provided with brake systems which will respond more rapidly, and absorb a greater amount of energy in a given time than was required of previous brake systems on slower trains, in order to insure their safe operation.

One object of the present invention is therefore to provide an improved disk brake mechanism particularly adapted for, though not limited to, use on modern railway train vehicles.

It is another object of the invention to provide an improved brake mechanism of the disk type comprising rotatable and non-rotatable friction brake elements and including means for dissipating the heat generated in these elements during frictional braking engagement thereof.

A further object of the invention is to provide an improved, relatively simple and compact disk brake mechanism adapted to be mounted as a unit directly on a wheel of a vehicle truck, such as is used on modern high speed trains.

Still another object of the invention is the provision of improved disk brake mechanism the wearing parts of which may be replaced easily without removal of the entire mechanism from its mounting.

Still another object of the invention is the pro vision of improved means, for supporting the rotatable and non-rotatable braking elements of the disk brake mechanism independently of the truck frame.

Other objects and advantages will be apparent from the following more detailed description of the invention.

In the accompanying drawings: Fig. 1 is an end elevational view of the improved brake mechanism as applied to a wheel of a wheel and axle assembly of a railway vehicle truck; Fig. 2 is a view taken in the direction of the arrow 2 in Fig. 1; Fig. 3 is a sectional view taken along the line 3--8 in Fig. 1; Fig. 4 is a sectional view of a portion of the brake mechanism showing in particular a release spring arrangement; Fig. 5 is an end elevation or face view of a rotatable brake element and rotatable supporting member assembly; Fig. 6 is a plan view of the rotatable supporting member; Fig. 7 is a perspective view of a portion of said rotatable supporting member; Fig. 8 is a top plan view of the mechanism taken in the direction of the arrow 8 in Fig. 1; Fig. 9 is a face view of one non-rotatable brake element; Fig. 10 is a sectional view of a portion of asimilar non-rotatable brake element; Fig. 11 is asectional view taken along the line. a l-ll in Fig.

9; Fig. 12 is a sectional view taken along the line lZ-ll in Fig. 9; and Fig. 13 is an elevation view of another portion of said non-rotatable brake elements.

General description of disk brake mechanism As shown in the drawings, the improved brake mechanism is associated with a railway vehicle wheel I, for the purpose of illustrating one application of the invention. The wheel l is provided with the usual flanged tread portion for engaging a rail 2, and with a center hub I in which there is secured the usual axle 4. The novel brake mechanism is preferably mounted inside the wheel I and comprises an annular rotatable supporting member 5 (Figs. 1, 3, 5 and 6), encircling the axle 4 and which is secured to the inner face of the center hub for rotation with the wheel in coaxial relation therewith. Rotatable annular friction brake elements 8 and I are provided encircling and carried by the supporting member 5 in axial alignment with the wheel I for rotation therewith. A non-rotatable supporting structure 8 is provided journaled on the supporting member 5. Fluid pressure brake cylinder devices 9 are provided carried by the supporting structure 8 for actuating non-rotatable annular friction braking elements I, II and I2 into frictional interengagement with the'rotatable triction brake elements 8 and 1. The rotatable elements 8 and I are interleaved with the non-rotatable elements It, II and I! which are slidably supported in axial alignment with said rotatable elements and the wheel I by non-rotatable tubular guide support torque members I: which are comprised in the non-rotatable structure 8. An annular non-rotatable retaining .member I4 is rigidly secured to one end of each of the torque members I! to absorb thrust of the brake elements during braking operations. An annular non-rotatable pressure element I5 is slidably mounted on the members I! between the brake cylinder devices 8 and the brake. elements for evenly distributing brake cylinder thrust to said elements. Compression release springs l8, l1 and I 8 are provided for urging the non-rotatable brake elements toward their release or rest positions, and compression release springs 08 and 20 are provided for urging the rotatable brake elements toward their corresponding release positions.

. 3 Detailed description of disk br lce'mechanism' Referring to Figs. 3; 5 and 6, thelsupportiiig ,member 5 is provided vwith a. radial flange 2| adapted to be mounted against the inboard end face of the wheel hub 3 coaxially therewith. Dowel bushings 22 extending through bores 23 r 38 and thereby define a release position of the provided in. and spaced circumferentially about 24 ln'the wheel hub 3. Each bushing 22 is provided with a central through bore which is threaded to accommodate a tie bolt 25 which bolt exthe flange 2|. project into spaced counter-bores tends from the outer face of the wheel hub 3 through bores disposed longitudinally through said hub. A shoulder 27' is. formed in each bushing 22 to cooperatewith'the outer face of the flange 2| so that action of the tightened bolts 25 on the bushings 22 is transmitted to said flange. The bushings are of close fit in the flange 2| and counter-bores 24, and act to accurately locate and support the member 5 on the wheel.

Referring to Figs. 3, 5, 6 and 'I, the rotatable supporting member 5 is provided with a plurality of T-shaped torque transmitting guide support members 23 which are spaced about and secured to the flange 2|. The members 28 are provided with integral ribs 28 depending from the inner surface thereof which are rigidly secured to a face of the flange 2! by means of welds 33.

Now referring to Figs. 5 and 6, the spaced torque transmitting members 28 on the member 5 define slots or grooves 3| bounded at their respective sides by shoulders 32 formed by the adjacent members 28 and extending longitudinally of said member.

Referring to Figs. 3 and 5, the rotatable annular friction elements 6 and I, carried by the member 5, each comprises two annular coaxially aligned rings 33, spaced apart by lu members 34 to the outer faces of which the rings 33 are rigidly secured," by welding or other suitable means, to form the body portion of the elements 6 and l. The lug members 34 are spaced circumferentially about the body portion rings 33 and are provided with inwardly projecting lugs 35 which extend into the slots 3| .in slidable con-'' with the member. 5 .a ii flremain, free .t gslideaxially relative thereto in'ithe'slots 3|. 1

or rest positions by action of the previously mentioned springs l9 and 20 which are arranged as follows:

One end' of each of the grooves 3| is closed by a retaining element 36 which is. removably secured by means of bolts 31 to the members 28. Opposite ends of alternate grooves 3| are closed by similar retaining elements 38 which are secured to the member 28 by bolts 39.

The release compression springs l9 are disposed in the alternate grooves 3| interposed between retaining elements 36 and lugs 35 of rotatable element 8 to urge said lugs to seat against projecting ends of stop rods 40 to define a release position of the rotatable element 6. The rods 40 extend freely through openings in lugs 35 of rotatable element 1 and are secured at their opposite ends to the retaining elements 38.

The release compression springs 20 are disposed in adjacent grooves 3| extending freely through spring openings in lugs 35 of rotatable element 6 and interposed between retainin elerotatable elements 1 with respect to the supporting member 5.

Now referring to Figs. 3, 4, 5 and'8, Fig. 5 in particular, each of the rotatable braking elements 6 and 1 is provided with removable arcuate brake shoes 4| spaced about the periphery thereof. Each brake shoe 4| is preferably made of rolled steel and provided with a plurality of spaced ventilating openings 42 .which' extend therethrough transversely of their arcuate length for aiding in dissipating the heat generated during braking operations, and for reducing the weight of the shoe. The shoes 4| are spaced apart to allow for expansion and contraction thereof to take place freely without their consequent warpage.

An opening 43 is provided at the ends of each shoe 4! to accommodate tapered lugs 44 of the lug member 34, which lugs 44 project outwardly from the rings 33. A tapered bearing member 45 is formed in the ends of each shoe 4| to cooperate with the tapered lugs 44 for transmitting torque from the shoes to the lug members 34. The tapered lugs 44 and the shoe bearing members 45 have sloping cooperating faces 45 and 47, respectively. The adjacent faces 46 on each pair of adjacent lug members 34 are parallel to each other and to the mating faces 41 of bearing member 45 of a respective brake shoe 4!. The shoes 4| are limited in inward move-.- ment by contact witha shoulder 48 formed in the lug members 34 at the base of their lugs 44, and are limited in outward movement by contact with a shoulder 49 formed by a removable keeper member 50.

Each keeper member 50 constitutes a retainin arm which spans the tapered ends of the two lugs 44 of each lug member 34 and thereby the interengaging and adjacent ends of two brake shoes 4|, and which is provided with an inwardly projecting rib 5| at each of its ends which forms a bearing surface to cooperate with "parallel outer faces of said two lugs for preventing longitudinal movement of said arm.

Referring to'Figs. 3,4,- 5 and s, the rotatable elements 6 and I are urged toward their release U-shaped securing members 52 are fitted over the; keeper members 50, each member 52 comprising two strap members 53 which project into accommodatin grooves 54 formed in opposite faces of the respective lug members 34 inside the rings 33. Pins 55 are provided for locking the strap members 53 to the body portions of the rotatable braking elementsG and I. The pins 55 extend through small bores 56 provided in the rings 33 and through registering bores 51 which extend through the lug members 34. The pins 55 are locked into place by twisted wires 58 extending through small transverse holes, located at opposite ends of said pins within the grooves 54 in the lug members. The outer ends of the pins 55 are substantially flush with the outer surfaces of the rings 33 and a transverse lot 59 is provided in one end of each pin to accommodate a screwdriver or similar tool for twisting the pins in the bores whereby the respective wires projecting through said holes engage with the side walls of the respective groove 54 and bend to form a type of lock member which will remain in place.

Referring to Figs. 3, 5 and 6 the rotatable supporting member 5 is provided with a supporting member hub or sleeve 60 extendin outwardly from the base of the integrally attached flange 2| coaxially of the wheel I. An annular shoulder Cl is formed in the hub or sleeve Ill adjacent to and spaced away from the flange II. A spacer ring 52 is provided seated against the shoulder ii. Two ball bearings $3 and C4 of equal size are provided, having inner rings 89 and 44, and outer rings i1 and 69, respectively. A cylindrical bearing housing 49 is provided encasing the bearings 63 and 44 mounted on the outer bearing rings 41 and il thereof. The inner rings 69 and II of bearings I3 and S4 are mounted on the outer cylindrical surface of the supporting member hub 89 to rotate therewith. The inner ring Ci of bearing 83 is located seated against the end of the spacer ring I, while the outer ring 41 ,vided separating inner bearing rings 65 and I,

and outer bearing rings 61 and 60, respectively.

6 annular disk-shaped non-rotatable supporting member 89 carried by the bearing housing is. The non-rotatable supporting member 88 comprises a radially projectin annular supporting flange I! which is integrally attached to an axially projectin hub 90 which is provided with an inwardly projecting annular mounting flange 9|.

The inner surface of the supporting member hub The spacer ring II has an inside diameter which is substantially equal to the'inside diameter of I1 and 99. An ofl groove I3 is disposed centrally about the outer periphery of the ring I2, and a through port 14 opens the groove 19 to the interior of the housing. An outer end spacer ring I! is interposed between the inner ring 88 of the bearing 64 and a retainer ring 76 which has screw-threaded connection with the outer end of the supporting member hub 60 for locking the bearing assembly in place. The inner end of the housing 89 is provided with an inwardly extending flange end wall I1 havin an inner annular shoulder to cooperate with the outer peripheral surface of the ring 62 to prevent bearing lubricant from thereby escaping the housing, and, to prevent dust from entering. The inner annular surface of the housing end wall TI is spaced away from the bearing 63 to form a chamber 18. An oil thrower ring 19 is inserted in an annular groove formed in the end of the ring 62 against which the inner bearing ring 65 seats. The ring II is shaped to project into the chamber I9 and is spaced a short distance away from the curved inner surface of the end wall 11. The outer end of the housing 69 is closedby an annular outer retaining wall member 8t shaped similar to the integral end wall 11 and removably secured to the outer end of the bearing housing 69 by means .of cap screws Ii one of which is shown in Figs.

1 and 3, the others being enclosed by a thin washer 82. The inner surface of the member 80 is shaped to define a chamber 83 with the outer surface of the bearing 64 and a similar oil thrower ring 84 is provided in an annular groove formed in the inner end of the spacer ring 15 seatedagainst the outer end of the inner bearings ring 8. The ring 84 projects into the chamber 43 spaced a short distance away from the inner surface of the member. An arcuate looking plate 95 is bolted to the outer end of the retaining ring 16 and overlapping the end of the hub iii. A pin 86 secured in a bore in the huh I extends therefrom and projects through one or another of a plurality of openings 81 in the plate 95 to cooperate with the walls of said opening for preventing rotation of the assembled retaining ring 16 relative to the supporting member hub 60.

Referring to Figs. 1 and 3, the non-rotatable supporting structure 8 comprises a substantially 94 is mounted on a peripheral shoulder formed in the outer end of the bearing housing 69. The non-rotatable supporting member 88 located and secured to the housing 69 by stud bolts 82 which extend through bores 99 spaced circumierentially about the flange 9i and which project into corresponding tapped holes which are open at the outer end of said housing. The thin annular washer 92 seats against the outer face of the supporting member mountin flange 9i and is provided with circumferentially spaced bores which register with the bores of said flange to accommodate the threaded projecting ends of the stud bolts 92 which hold said washer in place.

Referring to Figs. 1 and 2, th non-rotatable supporting member 89 is provided with a torque arm 94 which is disposed radially at the outer edge of the supporting flange 99 and rigidly secured thereto by welding or by any other suitable means. The torque arm 94 is provided with a webbed slot 95 which slidably engages with a torque rod 95 removably mounted in a torque rod hole in a stationary member 91 of the vehicle truck frame. The torque rod 94 is locked into place by an inverted U-shape locking pin 98 having two downwardly extending arms which project into accommodatings through bores provided in opposite ends of the torque rod 96 outside of the webbed slot 95.: The locking pin 98 is held in place by a spring clip 99 which is secured to the truck member 91. The flange 99 of the supporting member 98 is thus secured against rotation.

Referring to Figs. 3 and 8, the non-rotatable tubular torque members l3 arranged in a circle around the rotatable elements are provided with internal threads at their one end, which end is welded to the walls of through bores I00 spaced about the outer edge of the retaining member l4 which is the shape of an annular disk of greater outside diameter than the outside diameter of the rotatable elements 6 and 1. The members ii are therefore spaced from each other around the rotatable elements 6 and I and are rigidly secured by means of tie bolts lfll to the non-rotatable supporting member flange 89 against which their opposite ends seat. The tie bolts iiii project through bolt holes in flange 89 and into the members i9 to which the bolt ends have a screwthreaded attachment. The heads of bolts ill seat on the outer surface of the supporting flange 89. The annular retaining member I4 is thus removably and rigidly secured to the non-rotatable supporting flange I9.

The non-rotatable torque members I! slidably support, coaxial with the wheel i and against rotation therewith, the non-rotatable brake element l0 interposed between the annular retaining member l4 and the rotatable brake element 6, the non-rotatable brake element ii interposed between the two rotatable brake elements 6 and I, the non-rotatable brake element l2 and the annular non-rotatable pressure element i5 interposed between the rotatable brake element I and the supporting flange 89, in the order named. Each of the above named elements is provided with a plurality of spaced guide support slots I82 form jointsl06 and I01. .The single joint I! is removably secured together by screws I08 which are locked into place by'lock nuts I09; while the joints I06 may be secured by welds. The screw secured joint I01 renders itpossible, upon removal of the screws, to spring the overlapping ends of this joint apart sufficiently to pass over the axle 4 when it is desired to replace a friction element.

- The ends of each arcuate segment I04 are cut away to form an expansion space IIO adjacent each joint of the assembled body portion i03. Each of the arcuate segments is provided with one of the guide support slots I02.

Referring to Figs. 3, 4, 9, 10 and 13, each of the segments I04 of the non-rotatable elements I0 and I2 is provided with a plurality of tapered openings III extending from one face I I2 to the opposite face I I3 thereof. The ends of the openings III in the face II3 are larger than the ends of said openings in the face II2. A plurality of spaced apart brake shoes I I4 are cast on the face II2 of each segment I04 over groups of tapered openings I I I so that molten metal during pouring flows into said openings. When cooled, each shoe H4 is thereby provided with a plurality of integrally cast means for securing said shoe to its respective segment I04, against the face H2 thereof and also against twisting or turning thereon. The shoes II4 are spaced apart on the segments I04, as above mentioned and as shown on the drawing, to provide spaces to allow for expansion and contraction of said shoes during braking operations without consequent damage thereto.

Each of the non-rotatable friction brake elements I0 and I2 is provided with an annular heat dissipating ring II5 made of a highly heat conductive metal such as copper. The rings H5 are shaped to seat flatly against the outer annular surface of the connected faces II 3 of the segments I04 forming the steel body portion I03 for conducting heat away from said steel body portion communicated thereto from the shoes II4. Each annular ring I I5 is shaped to conform with the general contour of the body portion I03, and is provided with guide support slots I02 and expansion spaces H0 to register with congruous slots and spaces of said body portion for purposes above mentioned.

Referring to Figs. 3, 4, 9, 11, 12 and 13, the non-rotatable friction brake element II, interposed between the rotatable friction brake elements 6 and I, comprises a similar body portion I03 in the form of joined arcuate segments I04 preferably of rolled steel plate. The segments are similarly connected at overlapping ends I05 to form joints I06 secured by welds, with provision of one joint secured by screws I08 to allow for inserting and removing the element by springing it over the axle.

The body portion I03 of the non-rotatable element II is also provided with expansion spaces III and guide support slots I02.

A pluralityof arcuate heat dissipating segments H6 of highly conductive metal. such as copper, are provided on each of the opposite faces of the element II. Each segment. 0 is shaped congruously with the body portion segments I04- and each is provided with similar guide support slots I02. The length of the copper segments is less than the length of the steel segments I34. terminating short of the expansion spaces I II and the overlapping ends I05 of said steel segments. Each segment II 6 is also provided with openings III corresponding to the tapered openings ll! of elements I0 and I2 which register with corresponding openings H1 in the body portion 103 of element II. The openings I" are not tapered in the element II, however (Fig. 12).

The copper segments I I6 are arranged sandwich fashion on the steel segments I04 of the body portion, one copper segment on each side of the steel segment, and brake shoes IIB are cast over the copper segments, the molten metal flow- .ing into the registering openings II! in the segments H8 and I04 of copper and steel. When cooled, the cast metal forms two oppositely disposed shoes I I 8, one at each side of the body portion I04 in intimate contact with the outer surfaces of the copper segments IIS and integrally connected by cast metal within the openings ill. The shoes II8 thus cast serve to secure the copper segments III; to the steel segments I04 as well as secure said shoes to the body portion I03 in contact with said highly heat conductive copper segments.

It will be appreciated that with the non-rotatable elements I0, II and I2 in their respective slidably supported positions opposite the rotatable elements 6 and I as previously described, the shoes H8 and H4 disposed about the annular non-rotatable elements I0, II and 12, are so proportioned and arranged with respect to the shoes 4| of the rotatable elements 5 and I as to be engageable therewith upon slidable compression of the interleaved rotatable and non-rotatable elements. It should also be pointed out that the diameter of the outer peripheral surface of the non-rotatable elements I0, II and I2 from which the guide support slots I02 open is sufliciently greater than the outside diameter of the rotatable elements 6 and I as to allow said slots to be disposed outside the projected periphery of said rotatable elements.

Now referring to Figs. 3, 8 and 9, the release springs l6 are interposed between the non-rotatable brake elements II and I2, and spaced circumferentially about the center edges thereof, around the rotatable element 1, adjacent to alternate non-rotatable torque members I3. Dish-shaped washer members H0 are provided which receive opposite ends of each spring ii for location thereof. Each washer member II! is provided with a central bore to accommodate a stop rod I20 which extends therethrough and is secured at its one end to the non-rotatable pressure member I 5 and projects inwardly therefrom to extend through openings I2I and I22 provided in the non-rotatable brake elements I2 and II. A washer I23 is provided over the projecting end of each stop rod I20 and is held in place by a pin through the end of said rod, the washer I23 acting to limit movement of the nonrotatable element I I away from the non-rotatable element I2 'by springs I6, for thereby defining the release position of element I I with respect to element I 2. I

The pressure member I5 is urged to seat against the inner face of the supporting flange 89 by the compression release springs I1 which are spaced circumferentially about said flange and project from the outer face thereof. Each spring I1 encircles a stop rod I24 which is provided with a tapered end I25 secured in an accommodating tapered hole I26 in the member I5. The rods I24 project outwardly through relatively large bores I21 in the flange 89. Dish-shaped spring bearing members I28 are provided which encircle the rods I24 adjacent the tapered ends thereof, which members I28 form shoulders which seat on the outer face of the flange 89 to transmit thrust from the springs I1 thereto. The opposite ends of the springs I1 seat on cap washer members I29 which are removably secured to the outer pro- Jecting ends of the rods I24. A spring cover I30 is provided over each spring assembly and secured at one end to the respective spring bearing member I28.

It will be appreciated that action of the springs I1 urge the member I to a release or rest position against the supporting member flange 89 which locates the attached rods I20 to define the corresponding release or rest position of the nonrotatable element II.

The non-rotatable element I0 is urged to seat against the annular retaining member I4 by action of the compression springs I8, which are spaced about the outer edge of said element adjacent to alternate non-rotatable torque members I3. Rods I3I are provided having tapered ends I32 secured in tapered holes spaced circumierentially about the member I4. The rods I3I project inwardly through openings in the element I0, and mounted on the projecting ends thereof are washer members I33 and removable caps I34 which hold the outer washer members I33 in place on the rods. The compression springs I8 encircle the rods I3I and are interposed between the washer members I33 and the inner face of the member I4.

Now referring to Figs. 1, 3, and 8, the fluid pressure brake cylinder devices 9 are individual and are spaced circumferentially about the outer surface of the non-rotatable supporting flange 89.

Each brake cylinder device 9 comprises a casing I35 secured to the flange 89 by bolts I36 and is provided with a bore I31 opening at one end of the casing and closed at the opposite end by an end wall I38. A piston I39 is slidably disposed in bore I31, dividing said bore into an atmospheric chamber I40 and a pressure chamber I4I. A resilient diaphragm gasket I42 is provided on the pressure side of piston I39 which is adapted and arranged to cooperate with the cylindrical wall of chamber I40 to prevent leakage of fluid under pressure past the piston from chamber I. A piston release compression spring I43 is interposed between the supporting flange 39 of the non-rotatable structure 8 and each piston I39 in the atmospheric chambers I40. A dirt protector I44 is disposed in each atmospheric chamber I40 to prevent dirt from gaining access to the cylindrical surface of the bore I31 traversed by the piston. Each protector I44 comprises a rigid cup-shaped securing member I45 which is received in an accommodating cavity on the atmospheric side of each piston and is held in place therein by action of the spring I43, one end of which abuts thereagainst. frustrated conical shaped member I46 is provided each protector which is secured and sealed at its smaller end to the peripheral edge of the open end or the securing member I45 by means of a A resilient removable retainer ring I41. ,The larger end of the resilient member I46 is removably secured to the casing I35 at the otherwise open end of the bore I31 by a similar retaining ring I48. A hollow piston rod I49 is centrally disposed in each chamber I40 extending through a central opening in each protector member I45 and each is rigidly secured at one end to the piston I39. The opposite end of each rod I49 projects through a bore I50 in the supporting flange 89 for engagement with the annular pressure member I5.

Referring to Figs. 1 and 8, a brake pipe in the form of a flexible hose, I5I is provided for conveying fluid under pressure from a suitable source to the brake cylinder devices 9. The hose I5I is connected to a coupling I52 which is secured to the torque arm 94. A pipe I53 communicates the coupling I52 with two branch pipes I54 which are open to the pressure chambers I4I of the two adjacent brake cylinder devices 9 by way of the passages I55 in reinforced fitting members I56, bolted to the outside of the cylinder casings I35, and registering passages I51 in said casings. The pressure chambers I4I of the two brake cylinder devices 9 just mentioned are in turn open to the remaining brake cylinder pressure chambers I by way of pipes I58 and other corresponding passages I55 and I51, which other passages are not shown.

Assembling of the brake mechanism The brake mechanism is initially adapted to be assembled as a unit on, a bench or the like remote from the vehicle wheel to which it is to be applied. This unit is then secured to the vehicle wheel.

The assembling of each brake mechanism may be accomplished in the following manner; the various parts hereinbefore described as being welded together having already been secured in the proper working relation.

Assume that the brake mechanism is to be assembled on a horizontal flat surface or table, the annular retaining member I4 is laid flat on said surface disposing the tubular torque members l3 and rods I 3| attached thereto upward. The slots I 02 of the heat dissipating ring II5 are brought into registry with the projecting ends of the members I3 and with the openings in said ring for receiving rods I3I also in alignment, said ring is dropped into place against the member I4. The body portion I03 of the non-rotatable friction element I0 is similarly located and dropped into place on top of the ring II5 with the openings I02 in said portion encircling the rods I3I which project upwardly therethrough, and disposing the attached brake shoes II4 on the top. The springs I8 are then dropped into place encircling the rods I3I and resting on the upper face of the body portion I03 of the element I0. Next cap washer members I33 are introduced to the ends of the springs I0, pressed down and secured to the ends of the rods I3I by the caps I34, thereby compressing said springs between the element I0 and said members.

Now, separate and apart from the above assembly, the dowel bushings 22 are pressed into the bores 23 of the supporting member flange 2 I. The retaining elements 36 are bolted to the members 29 of the supporting member 5. The spacer ring 62 is slipped over the supporting member hub 60 and seated against the supporting member shoulder 6|. The housing 69 is slipped over the hub 60 with the flange end wall 11 thereof encircling the spacer ring 82, and the oil thrower ring I9 is inserted in place. The ball bearing 83 is inserted inside the housing on the hub followed by the spacer rings II and I2, the ball bearing 54, the'oil thrower ring 84, the spacer ring I5 and the wall member 80. The retaining ring I8 is then screwed onto the outer end of the hub 60 to secure the bearing and housing assembly into place on said hub.

' The supporting member 5 and associated parts just assembled is then dropped into place within the inner peripheral clearance of the annular retaining member I4 and non-rotatable element I resting on the flat surface, as previously described. Blocks may be used to raise the member 5 for proper orientation with respect to the retaining member I4 and element I0. The release springs I3, Fig. 3, are then inserted in their proper slots 3| between alternate retaining elements 36 against which the lower ends of said springs rest. The rotatable element 6, including the removably attached shoes 4I, is now slipped over the bearing housing 69, the lugs 35 of said element being properly oriented with respect to the slots 3I of the supporting member 5, and said element 6 is dropped into place with its lugs 35 registering with the shoulders 32 which define the sides of said slots 3I. The element 6 is thus supported horizontally by the springs I9 on which each alternate lug 35 thereof now rests. The slots I02 of the non-rotatable element II are next brought into registry with the upwardly projecting tubular torque members I3 and said element is dropped onto the rotatable element 6. The springs are then dropped into the spring openings through the lugs of the rotatable element 6, and the assembled rotatable element I, including its shoes H, is added in fashion, similar to the addition of the element 5, to rest on the upper ends of the springs 20. The retaining elements 38 and attached stops 40 are then secured to theupper ends of the members 28 by the bolts 39.

Again, separate and apart from the above assembly the non-rotatable element I2 including the copper ring H5 is next aligned so that the openings I2I thereof register with the projecting ends of the rods I20 attached to the annular pressure element I5, and then said element I2 is slid on said rods until the copper ring II5 thereof seats on said element I5. The washer members I I9 are then placed on each end of each of the springs I5 and these washer and spring assemblies placed on the rods I20 which project through central bores of said members I I9. Each of the springs I6 is next compressed until the outer washer member II9 thereon passes over a small bore I59 opening transversely through each rod I20, a nail or piece of stiff wire (not shown) is then inserted in the bore I59, and the spring is released to seat said outer washer member against said nail. The springs I8 and outer washer members I I9 are thus temporarily secured in place a substantial distance from the projecting ends of the rods I20 to facilitate further assembly of the brake mechanism as a. unit, as will be presently described, while the non-rotatabie element I2 is held seated against the pressure element I5.

slots I02 thereof register with the tubular members I3 and the ends of the downwardly projecting rods I20 register with the openings I22 of the element II, and dropped into place with said rods I20 projecting through the openings I22. The washers I23 are then slipped over the ends of the rods I20 and secured in'place by the respective pins. The nails or wires are now pulled from the rod bores I59 thus releasing the springs I6 which act to urge the non-rotatable elements II and I2 apart.

Assume that the brake cylinder devices 3 have been bolted to the supporting member flange 89 and connected by pipes I53 and I54, I53 to the coupling I52, the supporting member hub 30 is then slipped over the upper end of the bearin housing 69 and aligned so that the upwardly projecting rods I24 of the annular pressure element I5 project through the bores I21 of the supporting member flange 89 and the tie bolt holes in said flange register with the upper ends of the tubular members I3. The tie bolts IOI are then inserted andscrewed in place to secure the annular retaining member I4 rigidl to the supporting memberdlange 89. The thin washer 82 is placed on the outer face of the supporting member mounting flange 9| and the studs bolts 92 are then inserted through bores 93 in flange 9| and screwed in place in the aligned threaded bores in housing 69 to secure the supporting member 8 rigidly to the bearing housing 59.

The spring bearing members I28 are next dropped into place around the rods I24 to rest on the supporting member flange 89 around the bores I21. The springs I! are placed on the rods I24 to rest on the members I28, the cap washer members I29 are then placed on said rods compresing the springs, and the spring covers I30 secured in place to complete the assembly of the brake mechanism unit ready for securing to the wheel.

The brake mechanism unit is now positioned on the wheel I so that the rotatable supporting member flange bushings 22 fit into the wheel hub counter-bores 24. The bolts 25 are then inserted into the-outer ends of the wheel hub bores 25 and screwed into the bushings 22 to secure the brake mechanism unit to the wheel.

The wheel is then pressed on to the axle of a vehicle truck disposing the brake mechanism inboard of said wheel. The brake mechanism torque arm 94 is next raised into position in the truck member 91 and located so that the torque arm slot 95 registers with the torque rod hole in said member 91, the torque rod 95 is inserted in the slot 95 and through said hole, and the U-shaped locking pin 98 dropped into place. The

spring clip 99 is sprung to accommodate the lockmg pin 98 which is rocked under it and then said clip is released to lock said pin into position to prevent its being jarred out by any road shock transmitted from the wheel'rolling on the rail.

Thehrake pipe hose I5! is connected to the couphng I52 to complete the installation of the brake mechanismwhich is now ready for operaion.

Operation of the brake mechanism With the brake mechanism applied to th wheel as above described, if it is desired to brake said wheel, fluid under pressure is supplied via the p pe I53, pipes I54, passages [55 and I51, and pipes I58 to the pressure chambers I of the brake cylinder devices 9 wherein it acts on the brake cylinder pistons I39 toeifect movement thereof in the direction of the wheel I.

As the brake cylinder pistons I33 are thus operated they act through the piston rods I 49 to shift the annular pressure element I away from the supporting flange 83 along the tubular torque members I3 and against the opposing action of the springs II. The pressure element I5 thus carries the non-rotatable brake element I2 into engagement with the rotatable brake element I. Upon such engagement, the rotatable brake element I is picked up and moved, against the opposing action of the springs 20, along the slots 3I between the torque transmitting members 28 into engagement with the non-rotatable brake element II which is then picked up and moved along the tubular members I3 into contact with the rotatable brake element 6. Further movement carries the element I; along the slots 3I against the opposing action of the springs I3 until said element 5 moves into contact with the nonrotatable brake element III. At this time all of the brake elements are in contact and the brake shoes and friction surfaces thereof are in frictional interengagement. The release springs I6 will have been further compressed between the non-rotatable brake elements II and I2 during a the above described movements.

After the several brake elements are thus moved into frictional interengagement, the pressure of fluid acting on the brake cylinder pistons I39 tends to force said elements in the direction of the wheel I, while the thrust of such force is taken by the annular retaining member I4 which is rigidity secured by bolts IIII to the non-rotatable supporting member flange 39 to which the brake cylinder casings I35 are secured. The rotatable brake elements 6 and I, and the non-rolatable brake elements III, II and I2 are thus subjected to a squeezing action between the retaining member I4 and the pressure element I5. As a result of this action, the interengaging brake shoes of the non-rotatable elements III, II and I! cause a drag or restraining friction force on the brake shoes of the rotatable brake elements 6 and I thereby effecting braking of said rotatable elements, which braking is transmitted by way of the rotatable brake element lugs 35 and rotatable torque transmitting members 23 to the supporting member 5 and thence through the dowel bushings 32 to the wheel I for effecting braking thereof. The degree with which the rotatable elements and thereby the wheel I are braked, as just described,- depends upon the pressure of fluid supplied to chambers I4I acting on the brake cylinder pistons I33, as will be apparent. During braking the, shoulders defining the slots I02 in the non-rotatable elements I0, II and I2 bear against the tubular torque members I3 which transmit such torque forces to the non-rotatable supporting member flange 39 which in turn transmits said forces to the stationary truck member 31 (Fig. 1) by way of the torque arm 94, and the torque rod 96, whereby the non-rotatable brake elements III, II and I2 are held against turning.

When it is desired to eifect a release of the brakes after an application, fluid under pressure is vented from the brake cylinder pressure chambers I by way of pipes I58, I54, I53 and I5I, and passages I55 and I51, whereupon the release springs I6 and I1 acting on the non-rotatable brake elements II and I2, the release springs I3 and 20 acting on the rotatable brake elements 6 and I, and the piston release springs I43 are permitted to act to move said brake elements and the brake cylinder pistons I39 back to their release 1 positions previously described, in which positions the non-rotatable elements are disengaged from the rotatable elements, as shown in the drawings.

Operation of cooling arrangements Upon rotation of the rotatable brake elements 5 and I, the walls of the openings 42 of the brake shoes 4I act as centrifugal fan or blower blades which draw air from the inner periphery of said rotatable elements through said openings to the outer periphery of said elements. During braking, when the rotatable element brake Shoes H are in frictional engagement with the non-rotatable element brake shoe H4 and Ill, heat is generated by such engagement which is absorbed by said brake shoes. The air currents drawn through the openings 42, as above described, act to cool the brake shoes 4| of the rotatable elements 6 and I, and being discharged at the outer periphery thereof create turbulent air currents which sweep over the outer faces of the copper segments IIB of the non-rotatable brake element I I and thereby aid in cooling said segments which conduct heat away from the brake shoes III with which said copper segments are in contact. The copper rings I I5 of the non-rotatable elements I] and I2 aid in conducting the heat away from the brake shoes I" of said elements.

Servicing of the brake mechanism The brake mechanism can be serviced without dropping the axle or pulling the wheel. The entire mechanism can be disassembled from the rotatable supporting member 5 and strung along the axle 4 in the reverse order of the previously described assembly. Should it be desired to replace a brake shoe H on either of the rotatable brake elements I; or I, same can be done without removing the body portion of the element from the axle. To accomplish this, the keeper member securing pins 55 are punched out to shear the bent wires which act to lock them in place, thereby releasing the strap members 53 and keepers 50 to free the brake shoe to be replaced. The replacement shoe would then be inserted in position and secured in place by reassembling the keepers and strap members onto the body portion. If it is desired to replace any of the nonrotatable brake elements which may be worn. same can be done by springing the Joint I31 secured by the screws I08, which are first removed, and slipping the non-rotatable element over the axle. Any non-rotatable replacement element would similarly be sprung over the axle into its proper position thereon ready for reassembly in the brake mechanism. It can readily be seen that any other part of the brake mechanism which may be subject to wear can be serviced without removing the entire brake mechanism as a unit from the wheel and axle assembly, including the brake cylinder devices 3 which may be removed for servicing by removing the bolts I35 which secure the casing to the supporting flange II, and the bolts which secure the fitting members I53 to said casing.

Summary From the above description it will now be evident that the novel brake mechanism is relatively simple and compact in structure. The brake mechanism may be completely assembled a a unit and applied to the wheel before the wheel is pressed onto the axle. Service of the brake mechanism may be accomplished without dropping an axle or pulling a wheel since the elements and parts thereof may be disassembled around the axle and supported thereon in their proper order of assembly while wearing parts are replaced. Adequate provision is made for cooling the brake shoes, thereby adding to the prospective life there- While one illustrative embodiment of the invention has been described in detail it is not the intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims,

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A' disk brake mechanism for a railway vehicle wheel comprising a rotatable brake element secured to rotate with said wheel and having a plurality of openings extending therethrough from the inner edge to the outer edge thereof, the defining walls of which openings act as vanes for causing air currents to flow outward through said openings during rotation of said brake element, a

non-rotatable friction brake element comprising friction elements for engaging said rotatable brake element, heat dissipating elements of highly heat conductive metal in contact with said friction elements and extending therefrom into the region of said air currents, and actuating means for effecting interengagement between'said rotatable brake element and said non-rotatable friction brake element.

2. In a disk brake mechanism, in combination,

two rotatable brake elements havin a plurality of opening extending therethrough from the inner edges to the outer edges thereof and havingwardlyj therefrom into the region of said currents of air. 1

3. In a disk brake mechanism for a railway vehicle wheel, in combination, rotatable brake elements secured to rotate withsaid wheel and having a plurality of openings extending from the inner edges to the outer edges thereof and also having a plurality of radially extending expansfon slots in the braking faces thereof the walls of which openings and slots act as fan blades which create outwardly directed currents of air during rotation of said rotatable brake elements, a non-rotatable supporting structure surrounding said rotatable elements, said struc-' ture comprising a retaining member disposed opposite one end of 'said rotatable brake elements, a plurality of guide and support members rigidly secured at their one end to said retaining member, a supporting member secured to the opposite ends of said guide support members, nonrotatable brake elements disposed within and carried by said rotatable supporting structur said rotatable elements being interleaved with said non-rotatable brake elements, said non-rotatable brake elements comprising a plurality of segmental brake shoes spaced circumferentially thereabout for frictional engagement with saii rotatable brake elements, and highly heat conductive elements in contact with said shoes and extending therefrom into the region of said currents 0f ail.

4. In a disk brake mechanism for a railway vehicle wheel, in combination, a sleeve member secured to rotate with said wheel, a rotatable brake element carried by said sleeve member for rotation therewith, said brake element having a plurality of openings extending from the inner periphery to the outer periphery thereof, a first annular non-rotatable supporting member journaled on said sleeve member, torque transmitting guide and support members spaced around and secured at their one end to said first annular non-rotatable supporting member and extending over and spaced from the periphery of said brake element, a second annular non-rotatable supporting member secured to opposite ends of said guide support members, annular non-rotatable brake elements disposed one on each side of said rotatable brake element and carried by said guide support members and having a plurality of circumferentially spaced friction elements for engagement with said rotatable brake element, and annular heat conductive members interposed between said non-rotatable brake elements and said non-rotatable supporting members.

5. In a disk brake mechanism for a railway vehicle wheel, in combination, an annular supporting member secured to said wheel for retation therewith, a plurality of circumferentially spaced torque transmitting members secured to said supporting member and defining a plurality of grooves extending in the direction of said wheel, a first annular rotatable brake element encircling said members and having'inwardly projecting lugs slidably disposed in said grooves, a second rotatableannular brake element having similar lugs slidably disposed in said grooves and having openings therethrough within said grooves, first retaining elements closing the ends of said grooves adjacent to said first rotatable element, second retaining elements removably secured to said members and closing opposite ends of said grooves, stop rods secured to said second retaining elements and projecting therefrom through said openings into the path of movement of said lugs of said first rotatable element. and release compression springs interposed between the first retaining elements and the first rotatable element lugs for urging them to seat against the stopi'ods.

6. In a disk brake mechanism for a railway vehicle wheel, in. combination, an annular supporting element secured to rotate with said wheel, a plurality of circumferentiallyspaced torque transmitting'members secured to said supporting element and defining grooves extending axially of said wheel, a first annular rotatable brake element encircling said members and having inwardly projecting members slidably disposed in said grooves, said projecting members having spring openings therethrough within said grooves, a second rotatable element having inwardly projecting lugs slidably disposed in said grooves opposite to said first rotatable element, first retaining elements closing said grooves at their one end adjacent said first rotatable element, second retaining elements closing the opposite ends of said grooves, and release compres-- sion springs extending through said openings and interposed between said first retaining elements and s'aid'lugs for urging said lugs to seat against said second retaining elements.

7. In a disk brake mechanism for a railway vehicle wheel, in combination, an annular supporting element secured to rotate with said wheel, a plurality of torque transmitting members secured to and spaced about said supporting element and cooperating with each other to form axially extending guide slots, a first rotatable element having inwardly projecting members slidably disposed in said slots, 8. second rotatable element having inwardly projecting lugs slidably disposed in said slots opposite said projecting members, first retaining members closing the ends of said slots adjacent to said first rotatable element, second retaining members closing opposite ends of alternate slots adjacent to said second rotatable element, a stop member secured to each second retaining member and projecting therefrom through openings in said lugs of said second rotatable element into the path of movement of said projecting members, first release compression springs interposed between alternate first retaining members and said projecting members to urge said projecting members to seat against said rods, and second release compression springs interposed between said first retaining members and certain lugs of said second rotatable element to urge other lugs of said second rotatable element to seat against the second retaining members.

8. A disk brake mechanism for a railway vehicle wheel, comprising a first annular member, torque transmitting guide support members secured at their one end to said first annular member, a second annular member spaced away from said first annular member in coaxial relationship therewith and secured to opposite ends of said guide support members, means for securing said second annular member against rotation, a first non-rotatable brake element carried by said guide support members, first spring means for urging said first non-rotatable brake element to seat against said first annular member, a second non-rotatable brake element carried by said guide support members, second release spring means for urging said second non-rotatable brake element to seat against said second annular member, a rotatable brake element secured to rotate with said wheel and interposed between said nonrotatable brake elements for frictional engagement therewith, and brake cylinder means secured to said second annular member for effecting said engagement.

9. A disk brake mechanism for a railway vehicle wheel, comprising a sleeve member secured to rotate with said wheel, a first annular member journaled onto said sleeve member, means securing said first annular member against rotation, torque transmitting guide support members removably secured at their one end to said first annular member, a second annular member spaced away from said first annular member in coaxial relationship therewith and rigidly secured to opposite ends of said guide support members, a first non-rotatable element carried by said-guide support members, a first highly heat conductive element interposed between said first non-rotatable element and said first annular member, release spring means for urging said first non-rotatable element and the interposed heat conductive element toward said first annular member, a second non-rotatable element carried by said guide support members, a second highly heat conductive element interposed between said second non-rotatable element and said second annular member, spring members for urging said second non-rotatable element and the heat conductive element in contact therewith to seat against said second annular member, an annular rotatable brake element secured to rotate with said sleeve member and interposed between said first and second non-rotatable elements for frictional engagement therewith, said rotatable brake element having a plurality of openings therethrough extending from the inner peripheral edge to the outer peripheral edge thereof, and brake cylinder means secured to said first annular member for efiecting said frictional engagement.

10. In a disk brake mechanism for a railway vehicle wheel, in combination, a first backing,

member, torque transmitting guide support members secured at their one end to said first backing member, a second backing member secured to opposite ends of said guide support members and spaced away from said first backing member, means securing said second backing member against rotation, a first non-rotatable braking element disposed between said members and carried by said guide support members, spring means for urging said first non-rotatable braking element to seat against said first backing member, a second non-rotatable braking element disposed between said members and carried by said guide support members, a pressure member interposed between said second nonrotatable braking element and said second backing member and carried by said guide support members, first release spring means for urging said pressure member to seat against said second backing member, a third non-rotatable braking member disposed between said first and second non-rotatable brake elements and carried by said guide support members, spaced stop members secured at one end to said pressure member andprojecting therefrom through openings in said second and third non-rotatable elements, a stop element secured to the projecting end of each of said stop members between the first and second non-rotatable elements, and second release spring means for urging said second non-rotatable element to seat against said pressure member and for urging said third nonrotatable element to seat against the stop elements.

11. In a disk brake mechanism for a railway vehicle wheel, in combination, a rotatable supporting member comprising a sleeve, an annular flange integrally connected to one end of said sleeve, dowel bushings circumferentially spaced about said flange and projecting therefrom, bolts extending in an axial direction through said wheel and securing said dowel bushings in bores therein for securing said supporting member to rotate therewith in coaxial relationship, a plurality of torque transmitting guide support members secured to and circumferentially spaced apart about said fiange to define grooves extending in an axial direction, and a rotatable braking element having inwardly projecting lug members slidably disposed in said grooves. I

12. A disk brake mechanism for a railway vehicle wheel, comprising a sleeve member secured to rotate with said wheel, torque transmitting members secured to said sleeve member and spaced apart circumferentially thereabout to define grooves extending in a direction longitudinally of said sleeve member, annular rotatable braking elements encircling said torque members and slidably mounted in said grooves in coaxial relationship with said sleeve member, a first annular member journaled onto said sleeve member, means securing said first annular member against rotation, tubular guide support members secured to said first annular member projecting therefrom and spaced around said rotat- 19 able braking elements, a non-rotatable braking element carried by said guide support members and interleaved with said rotatable braking elements for frictional interengagement therewith, brake cylinder means secured to said first annular supporting member for compressing the interleaved braking elements to eifect said interengagement, and a second annular member secured to said guide support members for absorbing the thrust of said compressing.

13. A torque transmitting member for carryingand rotating an axially movable rotatable brake element of a disk brake mechanism of the type in which said element has a plurality of spaced inwardly projecting torque transmitting lugs, said member comprising a sleeve, an outwardly projecting radial flange integral with one end of said sleeve, and a plurality of individualspaced apart, substantially T shaped torque transmitting members arranged around said flange and comprising a first part extending radially of said flange and secured thereto and a second and integral part extending at right angles to said first part, longitudinally of said sleeve, adjacent faces oi each two of said second parts constituting guides for slidable contact with opposite sides of said lugs.

14. A torque transmitting structure for carrying and rotating an axialy movable rotatable brake element of a disk brake mechanism of the type in which said element has a plurality of spaced inwardly projecting torque transmitting lugs, said structure comprising a sleeve, an outwardly projecting radial flange integral with one end of said sleeve, said flange having a plurality of spaced through bores extending longitudinally of said sleeve, a torque transmitting dowel disposed in each of said bores and comprising a body portion extending through the bore and beyond one end of said sleeve and the adjacent face of said flange and an integral head engaging the opposite face of said flange, each dowel having an axially arrangd screw-threaded bore to receive a securing bolt, and a plurality of individual spaced apart, substantially T shaped torque transmitting members arranged around said flange and comprising a first part extending radially of said flange and secured thereto and a second and integral part extending at right angles to said first part, longitudinally of said sleeve, adjacent faces of each two of said second part constituting guides for slidable contact with opposite sides of said lugs.

15. A torque transmitting member for carrying and rotating an axially movable rotatable brake element of a disk brake mechanism of the type in which said element has a plurality of spaced inwardly projecting torque transmitting lugs, said member comprising a sleeve, an outwardly projecting radial flange integral with one end'of said sleeve, and a plurality of individual spaced apart, substantially T shaped torque transmitting members arranged around said flange and comprising a first part extending radially of said flange and secured thereto and a second and integral part extending at right angles to said first part, longitudinally of said sleeve, adjacent faces of each two of said second parts constituting guides extending longitudinally of said sleeve and parallel to the radius of said sleeve for slidable contact with opposite sides of said lugs.

16. A disk brake mechanism for application to the inner or inboard side of a vehicle wheel preparatory to mounting the wheel on an axle, said brake mechanism comprising a rotatable 20 sleeve member, rotatable and non-rotatable braking elements carried by said sleeve member and operative relative to said sleeve member to fric- -tionally interengage with each other, power means also carried by said sleeve member operative to actuate the brake elements, means for holding said sleeve member, friction braking elements and power means together as an operative unitary structure for application to said wheel, said sleeve member having an interior diameter great enough to accommodate the axle when the wheel is being pressed thereon, andmeans operative with said mechanism assembled into said unitary structure to secure said sleeve member to said wheel for rotation therewith.

17. A disk brake mechanism for a vehicle wheel comprising a sleeve, a flange integral with one end of said sleeve for attachment to said wheel, a pile of annular brake elements arranged in coaxial relation to said sleeve and comprising a plurality of non-rotatable brake elements and interleaved rotatable brake elements, a plurality of torque transmitting elements spaced around and secured to said flange and each adjacent pair providing a slot extending lengthwise of said sleeve, said rotatable brake elements comprising lugs extending into the slots between adjacent torque elements and having sliding contact with opposite walls of said elements, a first annular backing element journaled on said sleeve adjacent the non-rotatable brake element at the adjacent end of said pile, a second annular backing element disposed at the opposite end of said pile for supporting the adjacent non-rotatable brake element, a plurality of sleeves spaced from and arranged around the peripheries of said rotatable brake elements parallel to the axis thereof and integrally secured at one end to said sec ond backing element, the opposite ends of said plurality of sleeves engaging said first backing element, screw means rigidly securing said first backing element to said opposite ends of said plurality of sleeves, said non-rotatable brake elements having slots open at the peripheries thereof in which said plurality of sleeves are disposed, and a plurality of individual brake cylinder devices spaced apart around the face of said first backing element opposite said pile and removably secured thereto, and means including a rod extending from each brake cylinder device through an opening in said first backing plate for acting on the adjacent non-rotatable element for pressing said pile of elements into frictional interengagement against said second backing element.

18. A disk brake mechanism for a railway vehicle wheel, comprising a first annular member, torque transmitting guide support members secured at their one endto said first annular member, a second annular member spaced away from said first annular member in coaxial relationship therewith and secured to opposite ends of, said guide support members, means for securing said second annular member against rotation, a first non-rotatable brake element carried by said guide support members, means for securing said first non-rotatable brake element to said first annular member, a second non-rotatable brake element carried by said guide support members. release spring means for urging said second nonrotatable brake element to seat against said second annular member, a rotatable brake element secured to rotate with said wheel and interposed between said non-rotatable brake elements for frictional engagement therewith, and brake cylinder means secured to said second annular member for effecting said engagement.

19. A torque transmitting member for carrying and rotating anaxially movable rotatable brake element of a disk brake mechanism of the type in which said element has a plurality of spaced inwardly projecting torque transmitting lugs, said member comprising a sleeve, an outwardly projecting radial flange integral with one end of said sleeve, and a plurality of individual spaced apart, substantially T-shaped torque transmitting members arranged around said flange and comprising a first part extending radially of said flange and secured thereto and a second and integral part extending at right angles to said first part, longitudinally of said sleeve, said second arts forming grooves for slidable contact with pposite sides of said lugs.

20. A disk brake mechanism for application to the inner or inboard side of a vehicle wheel preparatory to mounting the wheel on an axle, said brake mechanism comprising a rotatable sleeve member, rotatable and non-rotatable braking elements carried by said sleeve member and operative relative to said sleeve member to frictionally interengage with each other, power means also carried by said sleeve member operative to actuate the brake elements, means for holding said sleeve member, friction braking elements and power means together as an operative unitary structure for application to said wheel, said sleeve member having an interior diameter sufiiciently great to accommodate said axle when said wheel is being pressed thereon, and means operative from the outboard face of said wheel for securing said sleeve member and thereby said unitary structure to said wheel.

21. In combination, a truck frame, an axle journaled in said frame, a wheel mounted on said axle for rotation relative to said frame, a sleeve member encircling said axle with clearance and removably secured to and carried by said wheel, rotatable braking elements splined to said sleeve member, non-rotatable braking elements interleaved with said rotatable breaking elements, power means journaled on said sleeve at one end of the interleaved braking elements for effecting frictional engagement therebetween, a thrust absorbing element disposed at the opposite end of said interleaved braking elements, rigid means supportingly connecting said thrust absorbing element with said power means and slidably supporting said non-rotatable braking elements, and torque transmitting means removably connected to said truck frame to prevent rotation of said power means and said non-rotatable braking elements with said wheel.

22. A brake mechanism adapted to be applied to and removed from, as a unit, the inboard side of a wheel in a railway vehicle wheel and axle assembly comprising an annular rotatable friction brake element, an annular non-rotatable friction brake element, brake cylinder means for effecting inter-engagement between the rotatable and non-rotatable friction brake elements for braking said wheel, a, rotatable structure carrying said rotatable friction brake element, a non-rotatable structure journaled on said rotatable structure carrying said rotatable element and brake cylinder means, and means for removably securing said brake mechanism as a unit to the inboard side of said wheel, said means being removable and replaceable from the outboard side of said wheel.

JOSEPH C. McCUNE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Wellman et al. Aug. 14, 1945 

